package li;

public class day99 {
    public static void main(String[] args) {
        StringBuilder sb= new StringBuilder();
        sb.append("红色").append("蓝色").append("绿色");
        System.out.println("反转前:"+sb);
        sb.reverse();
        System.out.println("反转后:"+sb);
        System.out.println("sb中字符个数:"+sb.length());
        String s=sb.toString();
        System.out.println("字符串:"+s);
    }

}
